In a conventional telephone network, each subscriber has a telephone terminal at which he can be reached in a specific location by means of a specific telephone number. In the final analysis, the telephone number is not assigned to the subscriber, but rather to the location. On the one hand, this subscriber cannot be reached with "his" number if he is located in a different place, and on the other, different persons, perhaps family members, can be reached with this number, although they are not listed in the telephone directory.
By contrast, in the mobile radio network, the site at which the subscriber's mobile radio set is located can always be reached by means of a specific telephone number, and thereby often the subscriber himself. Still, most mobile radio subscribers also have a "fixed network set", and thus a second telephone number in addition to the mobile radio set, mainly for reasons of cost. A caller has to know which of the two numbers he must dial. In practice, this is often done by trial and error. Technical solutions are also known for the trial and error method. In that case, every call that is not answered by a first terminal is switched to a second terminal after a predetermined time (e.g. after three rings), then perhaps even to a third terminal, or back to the first.
Solutions are also known whereby the subscriber must report to a central of some kind, at which terminal he is presently located. Calls to the subscriber are then switched to his central, from where they are routed to the selected terminal. The present invention starts with such a communications infrastructure, and builds on it.
The problem on which the present task is based is to reduce the cost to the subscriber of switching between the terminals under consideration.